The association of ABO blood groups and trauma outcomes: A retrospective analysis of 3779 patients

Background: There is currently a lack of understanding regarding the link between ABO blood types with outcomes of traumatically injured patients. The purpose of this study was to determine the association of ABO blood types with outcomes in traumatically injured patients separated by injury type. Methods: This retrospective study evaluated trauma patients at an urban, Level 1 trauma center from January 1, 2017, through December 31, 2017. Patients were excluded if they were pregnant or <16 years old. Recorded outcomes included: ABO blood group, mortality, Injury Severity Score (ISS), race, injury type, mechanism of injury, and complications. Data analysis was performed using descriptive statistics including Chi-squared, Kruskal-Wallis, and F-test calculations. Results: A total of 3779 patients were included in this study. No significant differences were present in mean age or ISS between blood types. In patients with penetrating injuries, blood type O was associated with a significant increase in mortality (P = 0.017), red blood cell transfusion (P = 0.027), and massive transfusion protocol (MTP) (P = 0.026) compared to non-O blood types. In patients with blunt injuries, blood type AB was associated with a significant increase in mortality rate compared to non-AB blood types (P = 0.03). Conclusion: ABO blood type is connected with an underlying process which affects trauma outcomes, including mortality. Blood type O is associated with increased blood transfusion, MTP, and mortality during the initial hospitalization following a traumatic penetrating injury, while blood type AB is associated with increased mortality during the initial hospitalization following a blunt traumatic injury.